Knockdown thatch umbrella



FIG. 1 is an enlarged perspective view of a knockdown thatch umbrella showing my new design;

FIG. 2 is a front elevation view thereof, with the rear, right side, and left side elevation views being identical;

FIG. 3 is a top plan view thereof; and,

FIG. 4 is bottom plan view thereof.

The broken lines are shown for the purpose of illustrating portions of the knockdown thatch umbrella that form no part of the claimed design. 

CLAIM The ornamental design for a knockdown thatch umbrella, as shown and described. 